Arrangement at keyboard

ABSTRACT

ARRANGEMENT AT KEYBOARD WHICH OVERCOMES THE FACTOR OF UNCERTAINTY CAUSED BY MECHANICAL VIBRATIONS IN CONVERTIONAL KEYBOARDS OF FORCED MAGNET CARRIER MOTION BY PROVIDING A SPRING MEANS ELIMINATING REBOUND OF THE MAGNET CARRIER.

Oct. 5, 1971 s. G. F. NORRMAN 3,610,059

ARRANGEMENT AT KEYBOARD Filed Oct. 27, 1969 United States Patent US. Cl. 74-102 2 Claims ABSTRACT OF THE DISCLOSURE Arrangement at keyboard which overcomes the factor of uncertainty caused by mechanical vibrations in conventional keyboards of forced magnet carrier motion by providing a spring means eliminating rebound of the magnet,

carrier.

At a keyboard of the type where the setting of a figure, letter or sign gives rise to electric impulses for controlling, for example, a punch, magnetic tape storage or the like, heretofore forced motion of a magnet carrier has been applied which actuates one or several reed relays which in their turn produce the electric impulse or impulses required.

The magnet carriers previously were designed so as to be moved entirely by force, but it was found that this involves difficulties owing to mechanical vibrations. When a certain number, letter or the like has a long mechanical travel, the heavy depression of a key gives rise to a mechanical vibration. As a result thereof, the set figure or letter simply gets lost when it should have been transferred to the tape storage. A construction of the type moved by force and subjected to vibration is found in the U.S.-built machine Digitronic 3207.

The function of the reed relay, as a matter of fact, is based on the fact that the circuit is closed when the keyoperated magnet carrier moves the magnet in one direction, and that the relay interrupts upon the return motion of the magnet.

This invention has as its object to overcome the aforesaid uncertain factor and is substantially characterized in that the magnet carrier at its motion in one direction is driven by a spring of such weakness that the key-actuated part, upon a strong depression, moves from the magnet carrier so as to be given time for a decay of its rebound prior to the arrival of the magnet carrier, thereby preventing rebound of the magnet carrier. The arangement according to the invention is intended for use, for example, in the aforesaid U.S.-built machine Digitronic 3207.

An embodiment of the invention is evident from the accompanying drawing which shows an arrangement according to the invention. In the drawing, 12 designates a stirrup actuated by numbered keys. Upon the depression of such a key said stirrup 12 is so actuated (via a linkage not shown) that it is caused to perform a downward swing about the shaft 13. If the machine is provided with a usual Sundstrand board, the articulated motion of the stirrup 12 will be short for the numbers 1-3, but rela- 3,610,059 Patented Oct. 5, 1971 'ice tively long for the numbers 7-9. It thereby was found that in the stirrup 12 mechanical vibrations are caused which at an operation of the magnet carrier 3 by forced motion as previously used involved the risk that the electric impulses simply were obliterated. According to the invention the magnet carrier 3 is given a design such that a spring 15 strives to pull downward the magnet carrier 3 which, however, is retained by a spring 16 actuating the stirrup 12. Said retaining effect is due to a shoulder 3a abutting to a projection 12a on the stirrup 12. The force of spring 16, thus, exceeds that of spring 15. The subtle feature of this arrangement is that the ,magnet carrier 3 driven by the spring 15 follows the stirrup 12 when the stirrup against the action of spring 16 suddenly is thrown down by a depression of a key. Therefore, possible vibrations of the stirrup 12 are given the time to decay prior to the arrival of the magnet carrier 3 in its lower position, and the magnet carrier 3, thus moves, without rebound. The magnet carrier 3, besides, co-operates with a holder 6 for a reed relay.

What is claimed is:

1. In a keyboard arrangement of the type wherein the setting of a key actuates a magnet carrier and said magnet carrier in turn actautes at least one reed relay to provide an electric impulse for controlling a punch or the like, the improvement which comprises a key actuated member in cooperative engagement with said magnet carrier and including means for biasing said key actuated memher to rebound to a first position upon removal of a strong key actuating force and, a weak spring biasing said magnet carrier against said means for biasing said key actuated member to allow said key actuated member to move away from said magnet carrier for a given time upon application of said strong key actuating force to said key actuated member to permit a rebound action of said key actuated member to decay and eliminate vibra.

tional rebounding of said magnet carrier against said key actuated member.

2. In a keyboard arrangement as recited in claim 1, the improvement wherein said key actuated member is a stirrup common to a plurality of keys on said keyboard and said means for biasing said key actuated member to rebound to said first position is a strong spring having sufficient force to lift said magnet carrier to a starting position upon removal of said key actuating force.

References Cited UNITED STATES PATENTS 3,363,737 l/1968 Wada et al 197-98 FOREIGN PATENTS 610,927 10/1960 Italy 74l04 EDGAR W. GEOGHEGAN, Primary Examiner B. GROSSMAN, Assistant Examiner US. Cl. X.R. l97 ---98, 106 

